Light-induced photon emission by rat hepatocytes and hepatoma cells

We have investigated spontaneous and light-induced photon emission of suspensions of rat hepatocytes and of HTC hepatoma cells. Rat hepatocytes exhibit spontaneous biophoton emission, but from hepatoma cells this was not detectable. In contrast, after irradiation with white light, the reemission intensity was found to be lower for hepatocytes than for the tumor cell line. Induced photon emission was neither influenced by anaerobiosis nor by the intactness of the cells. Cell-fractionation studies demonstrate that the induced photon emission was caused by the nuclear fraction and by isolated chromatin. Phenol-extracted DNA, however, has lost this capacity. Our data suggest that differences in the chromatin structure may explain the cell-specific induced photon emission.